Monday

Jun 3, 2019 at 8:47 AMJun 3, 2019 at 8:47 AM

Q: Greg, when was the first “tri-power” three-two-barrel carburetor setup released? Also, concerning the original “Six Packs” that Dodge and Plymouth introduced in mid-1969, was it the aluminum manifold or the cast iron that came first? Ernie M., Daytona Beach, Florida

A: Ernie thanks for your question. You are correct in calling the three-two-barrel (3x2) carburetor setup a “Tri-Power,” as it caught on real quick when they first appeared way back in 1957.

Actually, Pontiac officially coined the Tri Power moniker as its exclusive name back in 1957. However, the term took off like wildfire by hot rodders and regardless of brand, “Tri Power” was the nomenclature from that day forward regardless of make or model. It wasn’t until 1969 that MOPAR put out another very popular 3x2 setup dubbed “Six Pack” that to this day receives honorable mention in the 3x2 carb categorization history. MOPARS don’t have Tri Powers, they have Six Packs, period.

However, Pontiac did not release the first ever Tri Power setup and there’s some irony to the story.

The very first factory 3x2 Tri-Power setup became available on the 1957 Oldsmobile. It was called the W-code J2 option and topped off its powerful 371-cubic inch Rocket V8 with three Rochester two barrel carbs. The option cost just $83 extra, and the 3x2 carbs upped the Rocket V8 horsepower from 277 with a four barrel to an even 300. In 1958, the same option brought horsepower to 312 prior to Olds dropping its 3x2 option in ’59.

The irony involves sibling manufacturer Pontiac, as two weeks after the Oldsmobile J2 option became available, Pontiac released an exact same Rochester 3x2 Tri Power on several 1957 V8 models. Although missing being first to market by two weeks, two gentlemen were most responsible for Pontiac’s new high performance direction. The first was Pete Estes, who originated the pre-production 3x2 in 1956 while working for, here’s the irony, Oldsmobile. Estes was then named chief engineer at Pontiac in later 1956, and immediately implemented a Pontiac Tri Power 3x2 for 1957 as part of Pontiac’s new youth oriented direction.

The second person responsible for Pontiac’s youth oriented focus was Pontiac’s new brand manager Semon E. “Bunkie” Knudsen, who took Pontiac to the heights of motor racing popularity and worked closely with legendary master engine builder Smokey Yunick. This duo put the Pontiac brand into NASCAR victory lanes and Bunkie’s most famous quote, according to Smokey, was: “You can sell a young man’s car to an old man, but you can’t sell an old man’s car to a young man.” To make a long story short, beginning in 1957 and ending in 1966, Pontiacs offered Tri-Powers on V8s every year including 347, 370, 389, and 421 cubic inches.

Following the Olds-Pontiac Tri Powers, Cadillac offered 3x2s from 1958 to 1960 and Chevy joined the fray from 1958 to 1961 with its 348 V8. Ford offered numerous Tri Powers that they called “6V” setups on 390-406 engines in the early 1960s and first on the Thunderbird 390 in 1961. Chevy brought its Tri Power back from 1967-1969 on its 427 Corvettes, followed by the aforementioned MOPAR 440 Six-Pack Road Runner/Super Bee models. MOPAR continued through 1971 offering six packs and was the last American muscle car manufacturer to do so.

As for your MOPAR 440 Six Pack question, prior to the passing of Vic Edelbrock Jr., I personally asked him about his aluminum manifold as we were both attending a Performance Racing Industry trade show in Indianapolis. To answer your question, it was Edelbrock Jr.’s aluminum six pack intakes that came on the first 1,500 1969½ 440 six packs delivered.

However, as you already know, there were two distinct six pack intake manifolds, one the Edelbrock aluminum unit and the second, a cast iron Chrysler model. Edelbrock’s aluminum intakes for Chrysler included part No. P04529056 but due to demand and higher cost of the aluminum manifold versus cast iron, Chrysler went on their own with a cast iron intake for the remaining 1,819 more Six Packs produced that first half year. (For you Road Runner purists out there, Plymouth initially used the words “440 Six Barrel” instead of Super Bee’s “440 Six Pack” for model differentiation only).

Thus, the original ’69 Six Pack Super Bee and Road Runner models with the Chrysler part number Edelbrock aluminum manifolds are, in my opinion, worth more than their cast iron counterparts. Edelbrock still offers the aluminum Six Pack intake part No. 2475 for 440 V8s from 1968-71.

We’ll end with some trivia. Vic Edelbrock Jr. and fellow aftermarket superstar George Hurst, of Hurst 4-speed shifter fame, are the only two aftermarket legends to ever have their names on products Chrysler features in its original list of factory parts.

Thanks for your question Ernie and we sure covered some Tri Power/Six Pack history.Greg Zyla writes weekly on cars for More Content Now and GateHouse Media.

Never miss a story

Choose the plan that's right for you.
Digital access or digital and print delivery.